As automated assembly equipment and robots become more sophisticated, it is desirable to add the sense of vision to such devices. This would enable the equipment to locate the position of an object being manufactured, as well as to inspect the object for the presence of components or the proper location and size of specific features. To this end, various vision systems have been employed to generate a one or two dimensional electrical image of the workpiece which then can be electronically analyzed.
One of the problems that is often encountered in such vision systems is that they are relatively complex to set up and use. Typically, machine tools and other manufacturing equipment are operated by individuals who are not well versed in computer programming. Therefore, if the set up and analysis operations of the vision system requires significant computer programming steps, the equipment is not well suited for individuals whose primary skills lie in machine tool operation. It is therefore desirable to design a vision system which can be easily set up to analyze different types of workpieces and perform various decision making functions with respect to that analysis.
In addition, conventional programmable controllers which are employed to operate assembly lines and machine tools have input modules which are adapted to receive discrete input signals. Typically, such discrete input signals correspond to the opening or closing of a switch. Other ones of these input modules respond to an analog current, the magnitude of which varies in response to a sensed condition and then is evaluated by the control program of the programmable controller. Because of the large base of such installed programmable controllers, it is highly desirable to design a vision system which provides decision outputs that are compatible with the inputs to these existing controllers.